Furnace



June 2, 1936 R. voN MATTEKovll-l 2,042,643

FURNACE Filed May 25, 1934 Q Y im,

Patented June 2, 1936 UNiTED STATES PATENT OFFICE FURNACE Rudolf vonMattelmvich',v Rosalie, near Brisbane, Queensland, Australia 20 Claims.

1n a broad sense, this invention relates to furnaces in which a fuelsupply chute or shaft is isposed between a main and a subsidiary regratefor the purpose of enecting dehydration or carbonization of the fuel,and particularly refers to improvements in the construction of saidgrate shaft.

The present application is a continuation in part of my copendingapplication, Serial No.

f' 516,772, filed February 18, 1931.

One of the Objects of this invention is to provide a fuel chute or shaftfor supplying fuel to the fire of a boiler heating furnace and incirculating water from one boiler drum to another through tubes formingthe walls of the fuel chute.

Another object of this invention is toprovide a fuel chute or shaft forsupplying fuel to the fire of a boiler heating furnace, the walls of thechute being formed of water tubes through which water is circulated fromone boiler drum to another and in which the tubes of one of the wallsare connected at both ends to other tubes subjected to heat from afire-grate to provide for an independent circulation of water to absorba portion of the heat from said nre-grate.

Still another object of this invention is to provide a water cooled fuelchute for supplying fuel to the nre-grates of a furnace, in which chutethe fuel is heat treated to obtain the maximum amount of heat energytherefrom.

With these and other important objects in View, which may be incident tomy improvements, the invention resides in the parts and combinations tobe hereinafter set forth vand claimed, with the understanding that theseveral necessary elements comprising my invention may be varied inconstruction, proportions and arrangement, without departing from thespirit and scope of the appended claims.

ccording to the present invention, the fuel supply chute or shaft isformed by or between parallel legs of two separate tubular units oftubular structure, each unit being a complete water circulating systemin itself and in parallel with the boiler which the furnace is intendedto heat. Each unit comprises suitable headers connected with one anotherbyV rows of tubes across the width of the furnace. The parallel portionsof these two tubular structures are spaced apart to constitute betweenthem the grate supply chute which is preferably perpendicular.

In order to make the character and import of my invention clear,reference will be made to the accompanying drawing in which:

Figure 1 shows a longitudinal sectional eleva.- tion of one form of theapparatus in its relation to a boiler. Y

Figs. 2 and 3 are diagrammatic views of two modifications.

The grate shaft is formed by the combination of two entirely separateunits of tubular structures, each unit being a complete circulatingsystem in itself and being connected in parallel with the boiler. Thegrate supply shaft is bounded by the perpendicular tube walls BA and B1which extend across the full width of the furnace.

Unit B is shown in Fig. 1 as made up by means of three headers G, F, andFl which are connected with one another by rows of tubes B, 32 and D. Gis the receiving header, which is fitted with blow down connections (notshownl. F is the returning header from which risers H take the steam tothe top boiler drum J.

The inclined tubes B2 are exposedV to direct o radiation from grate A.Only one row of tubes is shown in the drawing, but two or more rows oftubes may be used in accordance with Vthe purpose of lowering thetemperature of Vthe fire-gases to a degree in agreement withrequirements and 25 prior to their passing through the fuel column.Circulation in this unit B, B2, andV D, as a system in itself isestablished by the horizontal tubes D which also support the roofing.tiles D1.

Unit B1 is shown as comprising twoheaders, 30

the upr header G1 being the receiving header. The lower header G2functions also as a mud drum and is therefore provided with blow-downconnections (not shown) The tube wall B1 bounding the grate shaft formsthe cold leg in this circulating system and the hot leg. is representedby the tube wall l-I2 which connects the headers directly with the steamdrum J of the boiler.

The tube wall H1 may be fully or only partly exposed to radiation fromgrate E by arranging the placing of tiles H30 forming the partitionbetween the subsidiary and main combustion chamber Vbehind or betweenthe tubes I-I.

Alternatively, as shown in Fig. 2 ofthe drawing, the lower header G20may be in communication withy the water drum J1 of the` boiler, and thenthe upper ends of tubes Hl'are expanded into header G10, from whichrisers H20V take the" steam to the top drum J of the boiler similarly asshown for unit B.

Unit B may also be constructed with two headers only by using tubessuitably bent' as in Fig'. 3. Drum G is, of course, connected as in Fig.1 to drum J1.

Passing through the spaces provided by the lower staggered portion ofthe tube wall B1 the flue gases Vfrom the subsidiary chamber, theexpelled vapor and volatiles from the fuel and the incoming top `airtravel over and above the hotter gases arising from grate E. The largedifference in density between the cooler mixture containing excess airand the hotter gases from the fire on the main grate induces readymingling and subsequently efficient combustion.

' The movable floor O controlsthe flow of fuel in both directions and inrequired proportions to the two furnace grates, respectively. This floorserves as a fuel shed for the main grate, whereas the refractory blocksS serve as a fuel shed for the subsidiary grate.

Top air enters the furnace through the opening P1 provided in the upperwall to the right of header G1 and directly above header G2.

The improvements herein described afford notable advantages shared bynone of the known combinations. The most salient advantages are:

Vl. The substantial addition of highly efficient heating surface to thatof the boiler;

2. Considerable gain of heat transfer, due to the front of the tubebundles in both furnaces being exposed to the radiant heat of the fuelbed; and Y 3. Highest possible combustion efficiency owing to:

' (a) The combustible gases emerging from the fuel chute or shafttogether with the vapor from the expelled moisture in the fuel, the fluegases from the subsidiary chamber and the incoming top air readilymingling with the gases arising from the main re by being made to travelover and above the hotter gases within the furnace, as this leads to aneddying action due to the greater density of the much cooler mixture.

(b) The largely reduced amount of excess air, due to the excess airadmitted into the subsidiary furnace becoming again available as top airin the main furnace. For instance, if onethird of the fuel is burnt inthe subsidiary furnace and two-thirds in the main furnace, and.

each furnace operated with 33% of excess air, then, yowing to the gasesentering into the main combustion chamber from the subsidiary chamberalready containing excess airrcorresponding with the requirements ofone-third of, the fuel, the weight of excess air to be added forcombustion in the main furnace is equivalent to that supplied into thesubsidiary furnace; thus, all of the fuel is burned with only 22% ofexcess air, although each furnace is operated individually with 33% ofexcess air.

While I have shown and described the preferred embodiment of myinvention, I wish it to be understood that I do not conne myself to theprecise details herein set forth by way of illustration as it isapparent that many changes and variations may be made therein by thoseskilled in the art, without departing from the spirit .of the inventionor exceeding the scope of the appended claims.

I claim as my invention:-

l. In a boiler heating furnace having a main and a subsidiarylire-grate, a fuel delivery chute above and between said main andsubsidiary re-grates for the pre-treatment of fuel prior to its deliveryon to the flre-grates, means for providingthe ready mingling of thecombustible gases with top air in a separateY space and the enforcedtravel of the gaseous mixture over and above the main nre, said separatespace being bounded by water tube walls, the tube wall facing the mainfire being partly exposed to radiant heat from the main grate, andpartitioning refractory tiles mounted on said tube wall facing the mainnre-grate.

2. In a furnace of the class described for heating a boiler having upperand lower drums connected by tubes, a main fire-grate and a subsidiaryfire grate, a vertically arranged fuel delivery chute positioned todeliver fuel in determined proportions to both of said re-grates, saiddelivery chute comprising a pair of spaced walls extending across saidfurnace, said walls being formed of tubes, the tubes in one wall havingtheir ends connected to tubes positioned above one .of the fire-gratesto provide for an independent circulation of water to absorb a portionof the heat radiated from said fire-grate, and means for separatelyconnecting the tubes of each wall to the upper and lower drums of theboiler for the circulation of water from one drum to the other throughthe wall tubes.

3. In a furnace of the class described for heating a boiler having upperand lower drums connected by tubes, a main fire-grate and a subsidiarylire-grate, a vertically arranged fuel delivery chute positioned todeliver fuel in determined proportions to both of said fire-grates, saiddelivery chute comprising a pair of spaced walls extending across saidfurnace, said walls being formed of tubes substantially vertically`arranged and horizontally spaced, upper and lower headers connectingthe upper and lower ends of said tubes, respectively, conduitsconnecting the lower drum rof the boiler with the lower header of oneset of wall tubes, conduits connecting the upper header of this set oftubes with the upper boiler drum, other conduits connecting the upperand lower headers of the other set of wall tubes with the lower andupper boiler drums, respectively, and still rother conduits ccnnectingthe upper header of said last-named set of wall tubes with the upperboiler drum.

4. In a furnace of the class described for heating a boiler having upperand lower drums connected by tubes, a main fire-grate and a subsidiaryfire-grate, a vertically arranged fuel delivery chute positioned todeliver fuel in determined proportions to both of said re-grates, saiddelivery chute comprising a pair of spaced walls extending across saidfurnace, said walls being formed of tubes substantially verticallyarranged and horizontally spaced, upper and lower headers connecting theupper and lower ends of said tubes, respectively, conduits connectingthe lower drum with one header of each set of wall tubes, and conduitsconnecting the upper rdrum with other headers of the sets of wall tubes,the tubes in one wall having their ends connected to tubes positionedabove one of the re-grates to provide for an independent circulation ofwater to absorb a portion of the heat radiated from said fire-grate.

5. In a furnace of the class described for heating a boiler having upperand lower drums connected by tubes, a main fire-grate and a subsidiarylire-grate, a vertically arranged fuel delivery chute positioned todeliver fuel in determined proportions to both of said fire-grates, saiddelivery chute comprising a pair of spaced walls extending across saidfurnace, said walls being formed of tubes substantially verticallyarranged and horizontally spaced, upper and lower headers connecting theupper and lower ends of said tubes, respectively, conduits connectingthe lower drum of the boiler with the lower header of one set of walltubes, conduits connecting the upper header of. this set of tubes withthe upper boiler drum, and other conduits connecting the upper and lowerheaders of the other set of wall tubes with the lower and upper boilerdrums, respectively, the tubes vin one wall having their ends connectedto tubes positioned above one of the fire-grates to provide for anindependent circulation of water to absorb a portion of the heatradiated from said fire-grate.

6. In a furnace of the class described for heating a boiler having upperand lower drums connected by tubes, a main fire-grate and a subsidiaryfire-grate, a vertically arranged fuel delivery chute positioned todeliver fuel in determined proportions to both of said re-grates, saiddelivery chute comprising a pair of spaced walls extending across saidfurnace, said walls being formed of tubes substantially verticallyarranged and horizontally spaced, upper and lower headers connecting theupper and lower ends of said tubes, respectively, conduits connectingthe lower drum of the boiler with the lower header of. one set of walltubes, conduits connecting the upper header of this set of tubes withthe upper boilei` drum, other conduits connecting the upper and lowerheaders of the other set of wall tubes with the lower and Lipper boilerdrums, respentively, and still other conduits connecting the upperheader of said last-named set of wall tubes with the upper boiler drum,the tubes in one wall having their ends connected to tubes positionedabove one of the re-grates to p-rovide for an independent circulation ofwater to absorb a portion of the heat radiated from said fire-grate.

'7. In a furnace of the class described for heating a boiler havingupper and lower drums connected by tubes, a main fire-grate and asubsidiary nre-grate, a vertically arranged fuel delivery chutepositioned to deliver fuel in determined proportions to both of saidre-grates, said delivery chute comprising a pair of spaced wallsextending across said furnace, said walls. being formed of tubessubstantially vertically arranged and horizontally spaced, upper andlower headers connecting the upper and lower ends of said tubes,respectively, conduits connecting the lower drum of the boiler with thelower header of. one set of wall tubes, conduits connecting the upperheader of this set of tubes with the upper boiler drum, other conduitsconnecting the upper and lower headers of the other set of wall tubeswith the lower and upper boiler drums, respectively, and heat resistingtile covering the portions of the conduits extending from the lowerheader of, one wall tube set to the upper drum of the boiler to reducethe heating effect on said conduits, the tubes in one wall having theirends connected to tubes positioned above one of the iire-grates toprovide for an independent circulation of water to absorb a portion ofthe heat radiated from said fire-grate.

8. In a furnace of the class described for heating a boiler having upper'and lower drums connected by tubes, a main fire-grate and a subsidiaryfire-grate, a vertically arranged fuel delivery chute positioned todeliver fuel in determined proportions to both of said re-grates, saiddelivery chute comprising a pair of spaced walls extending across saidfurnace, said walls being formed of tubes substantially vertically4arranged and horizontally spaced, upper and lower headers connecting theupper and lower ends of said tubes, respectively, conduits connectingthe lower drum with one header of each set of wall tubes, and conduitsconnecting the upper drum with other headers of the setsof Wall tubes,the tubes in each wall having their ends connected to tubes positionedabove the respective re-grates to provide for an independent circulationof water to absorb aportion of the heat radiated from the nre-grates.

9. In a furnace of the class described for heating a boiler having'upper and lower drums connected by tubes, a main fire-grate and asubsidiary iire-grate,-a vertically arranged fuel delivery chutepositioned to deliver fuel in determined proportions to both of saidfire-grates, said delivery chute comprising a pair of spaced Wallsextending across said furnace, said walls being formed of tubessubstantially vertically arranged and horizontally spaced, upper andlower headers connecting the upper and lower ends of said tubes,respectively, conduits connecting the lower boiler drum with the lowerheaders of-both sets of wall tubes, and' conduits connecting the upperboiler drum with the upper headers of both sets of wall tubes, the tubesin one wall having their ends connected to tubes positioned above one ofthe nre-grates to provide for an independent circulation of water toabsorb a portion of the heat radiated from said nre-grate.

l0. In a furnace of the class described for heating a boiler havingupper and lower drums connected by tubes, a main fire-grate and asubsidiary fire-grate, a vertically arranged fuel delivery chutepositioned to deliver fuel in determined proportions to both of saidfire-grates, said delivery chute comprising a pair of spaced wallsextending across said furnace, said walls being formed of tubessubstantially vertically arranged and horizontally spaced, upper andlower headers connecting the upper and lower ends of said tubes,respectively, conduits connecting the lower boiler drum with the lowerheaders vof both of wall tubes, and conduits connecting the upper boilerdrum with the upper headers of both sets of wall tubes, the tubes ineach Wall having their ends connected to tubes positioned above ti erespective fire-grates to provide for an independent circulation ofwater to absorb a portion of the heat radiated from the re-grates.

1l. In a furnace of the class described for heating a` boiler havingupper and lower drums connected by tubes, a main fire-grate and asubsidiary fire-grate, a vertically arranged fuel delivery chutepositioned to deliver fuel in determined proportions to both of saidre-grates, said delivery chute comprising a pair of spaced wallsextending across said furnace, said walls being formed of tubessubstantially vertically arranged and horizontally spaced, upper andlower headers connecting the upper and lower ends of said tubes,respectively, conduits connecting the lower druniof the boiler with thelower header of one set of wall tubes, conduits connecting the upper Yheader of this set of tubes with the upper boiler drum, other conduitsconnecting the upper and lower headers of the other set of wall tubeswith the lower and upper boiler drums, respectively, and heat resistingtile covering the portions of the conduits extending from the lowerheader of one wall tube set to the upper drum of the boiler to reducethe heating effect on said conduits.

l2. In a furnace of the class described for heating a boiler havingupper and lower drums connectedV by tubes, a main fire-grate and asubsidiary nre-grate, a vertically arranged fuel delivery chutepositioned to deliver fuel in determined proportions to both' of saidfire-gratas, said delivery chute comprising a pair of spaced wallsextending across said furnace, said walls being formed of tubessubstantially vertically arranged and horizontally spaced, upper andlower headers connecting the upper and lower ends of said tubes,respectively, tubes extending'horizontally over the subsidiaryfire-grate from the upper header of one set of wall tubes, a headerconnecting the free ends of the horizontal tubes, `tubes connecting thelast-mentioned header with the lower header of the wall tubes andpositioned to receive heat from the subsidiary fire-grate, and conduitsconnecting the upper andlower boiler drums with the headers of the Walltubes t provide for circulation of water from one drum to the other.

y 13. In a furnace of the class described for heating a boiler havingupper and lower drums connected by tubes, a main fire-grate and asubsidiary fire-grate, a vertically arranged fuel delivery ehutepositioned to deliver fuel in determined proportions to both of saidre-grates, said delivery chute comprising a pair of spaced wallsextending across said furnace, said walls being formed of tubessubstantially vertically arranged and horizontally spaced, upper andlower headers connecting the upper and lower ends of said tubes,respectively, tubes extending horizontally over the subsidiaryfire-grate from the upper header of one set of wall tubes, a headerconnecting the free ends of the horizontal tubes, tubes connecting thelast-mentioned header`with the lower header of the wall tubes andpositioned to receive heat from the subsidiary nre-grate, conduitsconnecting the said last-mentioned header with the upper boiler drum,conduits connecting the lower header of the tubes adjacent thesubsidiary grate with the lower boiler drum, and conduits connecting theupper and lower headers of the other set of wall tubes with the lowerand upper boiler drums, respectively.

le. In a furnace of the class described for heating a boiler havingupper and lower drums connested by tubes, a main fire-grate and asubsidiary fire-grate, a vertically arranged fuel delivery chutepositioned to deliver fuel in determined proportions to both of saidiire-grates, said delivery chute comprising a pair of spaced Wallsextending across said furnace, said walls being formed of tubessubstantially vertically arranged and horizontally spaced, upper andlower headers connecting the upper and lower ends of said tubes,respectively, tubes extending horizontally over the subsidiaryfire-grate from the upper header of one' set of wall tubes, a headerconnecting the free ends of the horizontal tubes, tubes connecting thelast-mentioned header with the lower header of the wall tubes andpositioned to receive heat from the subsidiary fire-grate, other tubespositioned over the main fire-grate and connecting the upper and lowerheaders of the chute wall tubes adjacent the main nre-grate, andconduits connecting the upper and lower boiler drums with the headers ofthe tubes to provide for circulation of Water through the tubesV fromone drum to the other.

15. In a boiler heating furnace having a main and a subsidiaryfire-grate, a vertical fuel delivery chute positioned above and betweensaid fire-grates for the pretreatment of fuel prior to delivery to saidgrates, said chute being formed of a pair of spaced tube walls extendingbetween ,walls of said furnace, an auxiliary tube Wall positionedbetween said subsidiary fire-grate and said fuel delivery chute, andmeans connecting all of said tube walls with the boiler for thecirculation of boiler water through said tube walls.

16. In a furnace of the Vcharacter described, a subsidiary nre-grate, amain fire-grate, a boiler, means for conducting hot products ofcombustion from said main and subsidiary flre-grates to said boiler, afuel delivery chute positioned above and between said fire-grates and inthe path of travel of the products of combustion from said subsidiaryfire-grate for the pretreatment and delivery of fuel to saidflre-grates, said chute being formed of water tube walls extendingbetween the side walls of the furnace, and an auxiliary water tube wallpositioned between said subsidiary firegrate and the fuel chute forreducing the temperature of the combustion products from the subsidiaryfire-grate before reaching the chute;

17. In a furnace of the character described, a subsidiary fire-grate, amain fire-grate, a boiler, means for conducting hot products ofcombustion from said main and subsidiary re-grates to said boiler, a.fuel delivery chute positioned above and between said fire-grates and inthe path of travel of the products of combustion from said subsidiarynre-grate for the pretreatment and delivery of fuel to said re-grates,said chute being formed of water tube walls extending between the sidewalls of the furnace, an auxiliary water tube wall positioned betweensaid subsidiary fire-grate and the fuel chute for reducing thetemperature of the combustion products from the subsidiary fire-gratebefore reaching the chute, and means connecting all of the water tubewalls with the boiler for the circulation of boiler water through saidwater tube walls.

18. In a furnace of the character described, a subsidiary fire-grate, amain fire-grate, a boiler, means for conducting hot products ofcombustion from said main and subsidiary re-grates to said boiler, afuel delivery chute positioned above and between said re-grates and inthe path of travel of the products of combustion from said subsidiaryfire-grate for the pretreatment and delivery of fuel to said re-grates,said chute being formed 0f water tube walls extending between the sidewalls of the furnace, an auxiliary water tube wall positioned betweensaid subsidiary fire-grate and the fuel chute for reducing thetemperature of the combustion products from the subsidiary re- Y gratebefore reaching the chute, means connecting the upper and lower ends ofsaid auxiliary tube wall with the upper and lower ends of the adjacenttube wall of the chute, and means connecting all of the water tube wallswith the boiler for the circulation of boiler water through said watertube walls.

19. In a boiler heating furnace having a main and a subsidiaryfire-grate, a vertical fuel delivery chute positioned above and betweensaid fire-grates for the pretreatment of fuel prior to its delivery ontothe fire-grates, said fuel delivery chute being formed between furnacewalls by spaced tube walls, means connecting each tube Wall with theboiler for the circulation of boiler water through said tube walls, anda refractory baffle associated with said chute for deflecting gases fromsaid subsidiary grate and from said chute over said main nre-grate toprevent their direct contact with heating surfaces of the boiler.

20. In a furnace of the character described, a subsidiary fire-grate, amain fire-grate, a boiler, means for conducting hot products ofcombustion from said main and subsidiary fire-mates to said boiler, afuel delivery chute positioned above and between said re-grates and inthe path of travel of the products of combustion from said subsidiaryfire-grate for the pretreatment and delivery of fuel to saidflre-grates, said chute comprising spaced Water tube walls, meansconnecting said Water tube Walls with the boiler for the circulation ofboiler water through said Walls, and a baffle positioned between saidfuel chute and said main fire-grate for deecting all gases down oversaid main re-grate.

RUDOLF voN MATTEKOVICH.

